- Routine or PRN consumption of the following herbal/dietary supplements are not permitted, if used within 2 weeks before the screening visit at doses higher than the recommended daily intake: Omega-3 fatty acids (> 1000 mg/day), Vitamin E (> 400IU/day). Ginkgo biloba, St. John's wort and ginseng are not permitted, if used at any dose within 2 weeks before the screening visit.